I'm not so sure, like I said Fandango doesn't usually use a placeholder if the runtime isn't known yet. For example, the
Justice League page has no runtime, neither does the page for
The Last Jedi. If it's not accurate, it's more likely just a mistake IMO. But it's certainly not outside the realm of possibility, we know that Mark Mothersbaugh has started working on the score so surely it stands that there must be a final cut. Taika said at SDCC that there was more than one cut of the film, one that ran at about 100 minutes and another that ran at about 2 hours. They may have decided to go with the longer one, it's worth remembering that it's not entirely Taika's decision. He may have wanted the shorter one, but Marvel Studios may have wanted the longer one, and it's ultimately their decision I would imagine.